I have a bit of confusion regarding "sb/sth. has/have been adjective./noun". For example, "I have been ill." "This festival has been great." "He has been a smart person." I am wondering about the time frame of them; I am not sure whether they mean "I have been ill in the past and I am still ill now"/"This festival is great from the past to the present"/"He was a smart person and still is", or "I was ill in the past but I have recovered now"/"This festival was great but now it's over or no longer great"/"He was smart but now is not".
I have consulted Google but there are many versions of explanations and I am a bit lost.